A United Nations treaty which bans children from being drafted into combat, comes into force on Tuesday, following its ratification by the required number of signatory states.

It is estimated that about 300,000 children are currently participating in fighting, in more than 35 countries.

The child that has been instilled with anger and poisoned, remains as a cultural landmine

Napoleon AdokFormer Sudanese child soldier

Ninety-four countries have now signed the optional protocol to the UN Convention on the Rights of the Child, which prohibits governments and rebel groups from deploying children under the age of 18 in any form of armed conflict.

With 14 countries ratifying the treaty since it was adopted by the UN General Assembly in May 2000, the protocol is now no longer optional, but enforceable.

Pressure

A spokesman from the Coalition to Stop the Use of Child Soldiers, says he is convinced the treaty will make a difference.

"With that international consensus, I think comes a powerful political sanction," said Rory Mungoven.

"Those that stand outside the consensus are under increased pressure. And I think we can see that having effect in the number of governments that have changed their position, the number of armed groups that have made public commitments on this principle, and you can see their response."

A programme in Sudan tries to rehabilitate child soldiers by doing ordinary things

Napoleon Adok, a former child soldier from Sudan, also welcomed the treaty, warning that children who were forced to take part in combat were often damaged for life.

"The child that has been instilled with anger and poisoned, remains as a cultural landmine, that lives for a long time as a cause of any instability. So for me personally, I am so grateful that this is a beginning of a wider process, and I expect many thing to happen."

The United Nations High Commissioner for Human Rights, Mary Robinson, and campaigners, will mark the treaty's enforcement with a special ceremony in the grounds of the UN's European headquarters in Geneva.